If Bitcoin is a scam, I will sell the coins in my hand as soon as possible. I believe that anyone will do so, because no one wants to believe in a scam, unless very few people do it!
Many newbies don't understand but bitcoin is not a scam but there are many ponzi schemes which are based on bitcoin and they are a scam. We should avoid those scam investment plans.
Investing directly in bitcoin is never a scam, rather it could be the best investment ever.